Systems for placing a coapting member between valvular leaflets

ABSTRACT

The present invention relates to devices and methods for improving the function of a defective heart valve, and particularly for reducing regurgitation through an atrioventricular heart valve—i.e., the mitral valve and the tricuspid valve. For a tricuspid repair, the device includes an anchor deployed in the tissue of the right ventricle, in an orifice opening to the right atrium, or anchored to the tricuspid valve. A flexible anchor rail connects to the anchor and a coaptation element on a catheter rides over the anchor rail. The catheter attaches to the proximal end of the coaptation element, and a locking mechanism fixes the position of the coaptation element relative to the anchor rail. Finally, there is a proximal anchoring feature to fix the proximal end of the coaptation catheter subcutaneously adjacent the subclavian vein. The coaptation element includes an inert covering and helps reduce regurgitation through contact with the valve leaflets.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.13/895,611, filed May 16, 2013, which claims priority under 35 U.S.C.§119 to U.S. Provisional Application Ser. No. 61/647,973, filed May 16,2012, and to U.S. Provisional Application Ser. No. 61/734,728, filedDec. 7, 2012, the disclosures of which are expressly incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention relates generally to devices and methods forimproving the function of a defective heart valve. The devices andmethods disclosed herein are particularly well adapted for implantationin a patient's heart for reducing regurgitation through a heart valve.

BACKGROUND OF THE INVENTION

The function of the heart may be seriously impaired if any of the heartvalves are not functioning properly. The heart valves may lose theirability to close properly due to e.g. dilation of an annulus around thevalve, ventricular dilation, or a leaflet being flaccid causing aprolapsing leaflet. The leaflets may also have shrunk due to disease,e.g. rheumatic disease, and thereby leave a gap in the valve between theleaflets. The inability of the heart valve to close properly can cause aleak backwards (i.e., from the outflow to the inflow side), commonlyreferred to as regurgitation, through the valve. Heart valveregurgitation may seriously impair the function of the heart since moreblood will have to be pumped through the regurgitating valve to maintainadequate circulation. Heart valve regurgitation decreases the efficiencyof the heart, reduces blood circulation, and adds stress to the heart.In early stages, heart valve regurgitation leaves a person fatigued orshort of breath. If left unchecked, the problem can lead to congestiveheart failure, arrhythmias or death.

Heart valve disease, such as valve regurgitation, is typically treatedby replacing or repairing the diseased valve during open-heart surgery.However, open-heart surgery is highly invasive and is therefore not anoption for many patients. For high-risk patients, a less-invasive methodfor repair of heart valves is considered generally advantageous.

Accordingly, there is an urgent need for an alternative device andmethod of use for treating heart valve disease in a minimally invasiveprocedure that does not require extracorporeal circulation. It isespecially desirable that embodiments of such a device and method becapable of reducing or eliminating regurgitation through a tricuspidheart valve. It is also desirable that embodiments of such a device andmethod be well-suited for treating a mitral valve. It is also desirablethat such a device be safe, reliable and easy to deliver. It is alsodesirable that embodiments of such a device and method be applicable forimproving heart valve function for a wide variety of heart valvedefects. It is also desirable that embodiments of such a device andmethod be capable of improving valve function without replacing thenative valve. The present invention addresses this need.

SUMMARY OF THE INVENTION

The present invention relates generally to devices and methods forimproving the function of a defective heart valve. The devices andmethods disclosed herein are particularly well adapted for implantationin a patient's heart for reducing regurgitation through a heart valve.The devices and methods disclosed herein are particularly useful inreducing regurgitation through the two atrioventricular (AV) valves,which are between the atria and the ventricles—i.e., the mitral valveand the tricuspid valve.

In one embodiment, the device comprises: an anchor to deploy in thetissue of the right ventricle, a flexible anchor rail connected to theanchor, a coaptation element that rides over the anchor rail, a catheterattached to the proximal end of the coaptation element, a lockingmechanism to fix the position of the coaptation element relative to theanchor rail, and a proximal anchoring feature to fix the proximal end ofthe coaptation catheter subcutaneously in the subclavian vein.

In another particular embodiment, the coaptation element consists of ahybrid structure: a series of a plurality (preferably three or more)flexible metallic struts to define a mechanical frame structure or acompressible biocompatible material, and a covering of pericardium orsome other biocompatible material to provide a coaptation surface aroundwhich the native leaflets can form a seal. The flexible struts desirablyattach to a catheter shaft on their proximal and/or distal ends, andcollapse into a smaller diameter in order to be delivered through a lowprofile sheath. In particular, the struts attach on one end or both to acatheter shaft, and are complete or interrupted, they typically extendthe length of the element, extend out or inwards, and may be discretestruts or a more connected mesh. The mechanical frame typically expandsto the larger shape passively upon exiting a protective sheath via shapememory properties (e.g. Nitinol), but could also be expanded vialongitudinal compression of the catheter, a shape memory balloon or someother external force. Additionally, the coaptation element can be anopen or closed structure, any biocompatible material and framework thatallows for compressibility for delivery and expands either actively orpassively upon delivery, can be various shapes, and can be a passive oractive element that is responsive to the cardiac cycle to change shapesto accommodate the regurgitant orifice.

One particular beating heart method includes delivering a coaptationmember to a position within native tricuspid heart valve leaflets toreduce regurgitation therethrough. A ventricular anchor advances on thedistal end of a flexible rail from above the native tricuspid annulusinto the right ventricle. The ventricular anchor is anchored within theright ventricle, and a coaptation member on a distal end of a deliverycatheter is advanced over the flexible rail until the coaptation memberis positioned within the native tricuspid heart valve leaflets. Thephysician adjusts the position of the coaptation member within thetricuspid annulus under visualization to reduce regurgitation throughthe tricuspid valve. Subsequently, the position of the delivery catheteris locked relative to the flexible rail by clamping a locking colletcarried by the catheter onto the flexible rail, and the locking colletis subcutaneously secured outside the subclavian vein. Desirably, thelocking collet includes two internally threaded tubular grips eachattached to separate sections of the delivery catheter that engaged acommon externally threaded tubular shaft member through which theflexible rail passes. A tubular wedge member interposed between thetubular shaft member and the flexible rail cams inward upon screwing thetubular grips toward each other over the tubular shaft member.

Another beating heart method described herein for reducing regurgitationcomprises advancing a ventricular anchor on the distal end of a flexiblerail from above the native tricuspid annulus into the right ventricle,then advancing a catheter having a balloon thereon over the flexiblerail until the balloon is positioned substantially within the tricuspidheart valve leaflets. The balloon on the catheter is inflated to centerthe flexible rail within the tricuspid annulus, and the flexible railfurther advanced until the ventricular anchor is located approximatelyat the apex of the right ventricle, whereupon the ventricular anchor isanchored within the right ventricle. The catheter having the balloon maybe the same as the catheter having the coaptation member, or anaccessory catheter may be used. The physician then advances a coaptationmember on a distal end of a delivery catheter over the flexible railuntil the coaptation member is positioned within the native tricuspidheart valve leaflets. If an accessory catheter is used, the physicianfirst removes the accessory catheter from the flexible rail. Theposition of the coaptation member within the tricuspid annulus isadjusted under visualization to reduce regurgitation through thetricuspid valve, and the position of the delivery catheter lockedrelative to the flexible rail.

A still further beating heart method of delivering a coaptation memberto a native tricuspid heart valve leaflets includes again advancing aventricular anchor on the distal end of a flexible rail from above thenative tricuspid annulus into the right ventricle, and anchoring theventricular anchor within the right ventricle. A coaptation member on adistal end of a delivery catheter advances over the flexible rail untilthe coaptation member is positioned within the native tricuspid heartvalve leaflets. The coaptation member on the delivery catheter is thensecured to a point above the tricuspid annulus and within a direct lineto the tricuspid annulus. The physician adjusts the position of thecoaptation member within the tricuspid annulus under visualization toreduce regurgitation through the tricuspid valve, and locks the positionof the delivery catheter relative to the flexible rail.

The coaptation member may connect via a tether to a stent secured withina coronary sinus opening to the right atrium, or the coaptation memberon the delivery catheter may be suspended within the annulus viaflexible cables to a pair of anchors secured directly to the tricuspidannulus. Alternatively, the delivery catheter connects via an adjustablesleeve and a rod to an anchor secured within a coronary sinus opening tothe right atrium, the adjustable sleeve and rod permitting adjustment ofthe relative positions of the anchor and the coaptation member. Anotherconfiguration involves connecting the delivery catheter directly to thesuperior vena cava via an anchor. Still further, the coaptation membermay connect via a connecting wire or rod to two stent structures, oneexpanded in the superior vena cava and the other in the inferior venacava.

In one embodiment, a spring is provided on the flexible rail between thecoaptation member and the ventricular anchor so that the coaptationmember can move axially with respect to the tricuspid annulus fromcompression and expansion of the spring. In another configuration, thedelivery catheter includes a pair of relatively flexible regionsdirectly proximal and distal to the coaptation member and a distalsection of the delivery catheter locks down on the flexible rail. Thestep of adjusting the position of the coaptation member within thetricuspid annulus thus includes advancing and compressing the deliverycatheter to cause the two flexible sections to buckle and displace thecoaptation member laterally with respect to the catheter axis. Theventricular anchor may comprise a pair of concentric corkscrew anchors,one having a clockwise orientation and the other having acounterclockwise orientation. The coaptation member preferably comprisesa frame form from a plurality of struts that supports a bell-shapedtissue cover formed by one or more panels of bioprosthetic tissue orflexible polymer sewn around the struts of the frame, the coaptationmember being open toward the right ventricle and closed toward the rightatrium.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify various aspects of embodiments of the presentdisclosure, a more particular description of the certain embodimentswill be made by reference to various aspects of the appended drawings.It is appreciated that these drawings depict only typical embodiments ofthe present disclosure and are therefore not to be considered limitingof the scope of the disclosure. Moreover, while the figures may be drawnto scale for some embodiments, the figures are not necessarily drawn toscale for all embodiments. Embodiments of the present disclosure will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings.

FIG. 1A is a cutaway view of the human heart in a diastolic phaseshowing introduction of an anchoring catheter into the right ventricleas a first step in deploying a device of the present application forreducing tricuspid valve regurgitation;

FIG. 1B is a cutaway view of the human heart in a systolic phase showingretraction of the anchoring catheter after installing a device anchor atthe apex of the right ventricle;

FIGS. 2A-2C are detailed views of installation of an exemplary deviceanchor by the anchoring catheter;

FIGS. 3A and 3B are sectional views of the right atrium and ventriclethat illustrate deployment of a regurgitation reduction device includinga delivery catheter advanced along an anchor rail to position a coaptingelement within the tricuspid valve;

FIG. 3C is a sectional view of the right atrium and ventricle in systoleshowing a frame-type collapsible coapting element, while FIG. 3D is aview looking down on the tricuspid valve showing the leaflets closedaround the frame;

FIGS. 3E and 3F are views similar to FIGS. 3C-3D with the tricuspidvalve open in diastole permitting blood flow around the frame-typecoapting element;

FIGS. 4A-4C are perspective and longitudinal sectional views of alocking collet shown proximally positioned on the catheter of FIGS. 3Aand 3B that is used to fix the position of the delivery catheter andcoapting element relative to the anchor rail;

FIG. 5 is a broader view of the final configuration of the regurgitationreduction device of the present application with a coapting elementpositioned within the tricuspid valve and a proximal length of thedelivery catheter including the locking collet shown exiting thesubclavian vein to remain implanted subcutaneously;

FIG. 5A is a schematic diagram of a representative coapting element anda pair of native tissue leaflets indicating certain key dimensions usedin constructing the coapting element;

FIGS. 6A-6C illustrate a coapting element having a series of alignedelongated members showing the tricuspid valve in both diastole andsystole, respectively;

FIGS. 7A/7B show a coapting element having a more conventional balloonshape with the tricuspid valve in systole, while FIGS. 8A/8B show thesame coapting element and the tricuspid valve in diastole;

FIGS. 9A-9B are sectional views of the heart illustrating aregurgitation reduction device positioned in the right atrium/rightventricle and having a three-sided frame as a coaptation element;

FIGS. 10A and 10B are elevational and end views of the coaptationelement from FIGS. 9A-9B;

FIG. 11A shows a sheet of bioprosthetic tissue, and FIG. 11B illustratesa coaptation element formed from rolling the sheet of tissue into acylinder;

FIGS. 12A-12C are longitudinal sectional views of an “active” coaptationelement of the present application forming several different shapes;

FIGS. 13A and 13B are schematic views of an alternative coaptationelement having a plurality of independently rotating rectangular frameswhich dynamically react to forces exerted thereon by the tricuspid valveleaflets;

FIGS. 14A/14B and 15 are views of an alternative coapting element havinga cage structure and ball valve therein, also showing interaction withthe tricuspid valve leaflets;

FIG. 16 is a view of another coapting element having a “sail” extendinglaterally from one side that catches regurgitant flow and adjusts theposition of the coapting element;

FIGS. 17A and 17B are views of a coapting element having acircumferential skirt extending outward therefrom positioned within thetricuspid valve leaflets, and FIGS. 18A-18B are enlarged views of thecoapting element with the skirt contracted and expanded, respectively;

FIGS. 19A and 19B show an alternative regurgitation reduction devicehaving a flapper valve that interacts with the tricuspid valve leafletsand is anchored by a stent within a coronary sinus opening to the rightatrium;

FIGS. 20A and 20B are systolic and diastolic views, respectively, of atricuspid valve interacting with a coil-spring coapting element anchoredby a stent within a coronary sinus;

FIGS. 21A and 21B are sectional views of the heart in diastole andsystole, respectively, showing a regurgitation reduction device which ismounted to the apex of the right ventricle with a spring that permits acoapting element to move in and out of the right ventricle in accordancewith the cardiac cycle;

FIGS. 22 and 23 are views of alternative anchoring members utilizingcoil springs;

FIG. 24 is a partial sectional view of an alternative anchoring devicehaving concentric corkscrew anchors, while FIGS. 24A-24C illustratesteps in installation of the anchoring device;

FIGS. 25 and 26 are views of still further anchoring members of thepresent application;

FIGS. 27A and 27B show operation of a centering balloon that helpsensure proper positioning of an anchoring member at the apex of theright ventricle;

FIG. 28 illustrates a step in directing an anchoring catheter to theapex of the right ventricle using an L-shaped stabilizing cathetersecured within a coronary sinus;

FIG. 29 schematically illustrates a stabilizing rod extending laterallyfrom a regurgitation reduction device delivery catheter in the rightatrium above the tricuspid valve;

FIG. 30 illustrates an adjustable stabilizing rod mounted on thedelivery catheter and secured within the coronary sinus;

FIG. 31 illustrates an alternative delivery catheter having a pivotjoint just above the coapting element;

FIGS. 32A and 32B show two ways to anchor the delivery catheter to thesuperior vena cava for stabilizing the coapting element;

FIGS. 33A and 33B show a regurgitation reduction device having pullwires extending therethrough for altering the position of the coaptingelement within the tricuspid valve leaflets;

FIG. 34 shows a regurgitation reduction device anchored with stents inboth the superior and inferior vena cava and having rods connecting thestents to the atrial side of the coapting element; and

FIGS. 35A-35C and 36A-36B are schematic views of a coapting elementmounted for lateral movement on a flexible delivery catheter thatcollapses and allows rotation for seating centrally in the valve planeeven if the delivery catheter is not central.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description refers to the accompanying drawings, whichillustrate specific embodiments of the invention. Other embodimentshaving different structures and operation do not depart from the scopeof the present invention.

Exemplary embodiments of the present disclosure are directed to devicesand methods for improving the function of a defective heart valve. Itshould be noted that various embodiments of coapting elements andsystems for delivery and implant are disclosed herein, and anycombination of these options may be made unless specifically excluded.For example, any of the coapting elements disclosed may be combined withany of the flexible rail anchors, even if not explicitly described.Likewise, the different constructions of coapting elements may be mixedand matched, such as combining any tissue cover with any inner flexiblesupport, even if not explicitly disclosed. In short, individualcomponents of the disclosed systems may be combined unless mutuallyexclusive or otherwise physically impossible.

FIGS. 1A and 1B are cutaway views of the human heart in diastolic andsystolic phases, respectively. The right ventricle RV and left ventricleLV are separated from the right atrium RA and left atrium LA,respectively, by the tricuspid valve TV and mitral valve MV; i.e., theatrioventricular valves. Additionally, the aortic valve AV separates theleft ventricle LV from the ascending aorta (not identified) and thepulmonary valve PV separates the right ventricle from the pulmonaryartery (also not identified). Each of these valves has flexible leafletsextending inward across the respective orifices that come together or“coapt” in the flowstream to form the one-way fluid occluding surfaces.The regurgitation reduction devices of the present application areprimarily intended for use to treat the atrioventricular valves, and inparticular the tricuspid valve. Therefore, anatomical structures of theright atrium RA and right ventricle RV will be explained in greaterdetail, though it should be understood that the devices described hereinmay equally be used to treat the mitral valve MV.

The right atrium RA receives deoxygenated blood from the venous systemthrough the superior vena cava SVC and the inferior vena cava IVC, theformer entering the right atrium above, and the latter from below. Thecoronary sinus CS is a collection of veins joined together to form alarge vessel that collects deoxygenated blood from the heart muscle(myocardium), and delivers it to the right atrium RA. During thediastolic phase, or diastole, seen in FIG. 1A, the venous blood thatcollects in the right atrium RA is pulled through the tricuspid valve TVby expansion of the right ventricle RV. In the systolic phase, orsystole, seen in FIG. 1B, the right ventricle RV collapses to force thevenous blood through the pulmonary valve PV and pulmonary artery intothe lungs. During systole, the leaflets of the tricuspid valve TV closeto prevent the venous blood from regurgitating back into the rightatrium RA. It is during systole that regurgitation through the tricuspidvalve TV becomes an issue, and the devices of the present applicationare beneficial.

Regurgitation Reduction System:

FIGS. 1A and 1B show introduction of an anchoring catheter 20 into theright ventricle as a first step in deploying a device of the presentapplication for reducing tricuspid valve regurgitation. The anchoringcatheter 20 enters the right atrium RA from the superior vena cava SVCafter having been introduced to the subclavian vein (see FIG. 5) usingwell-known methods, such as the Seldinger technique. More particularly,the anchoring catheter 20 preferably tracks over a pre-installed guidewire (not shown) that has been inserted into the subclavian vein andsteered through the vasculature until it resides at the apex of theright ventricle. The physician advances the anchoring catheter 20 alongthe guide wire until its distal tip is touching the ventricular apex, asseen in FIG. 1A.

FIG. 1B shows retraction of a sheath 22 of the anchoring catheter 20after installing a device anchor 24 at the apex of the right ventricleRV. The sheath 22 has desirably been removed completely from thepatient's body in favor of the second catheter, described below.

First, a detail explanation of the structure and usage of an exemplarydevice anchor 24 will be provided with reference to FIGS. 2A-2C. FIG. 2Ais an enlargement of the distal end of the anchoring catheter sheath 22in the position of FIG. 1A. The device anchor 24 is seen within thesheath 22 positioned just within the distal end thereof. The deviceanchor 24 attaches to an elongated anchor rail 26, which in someversions is constructed to have good capacity for torque. For instance,the anchor rail 26 may be constructed as a braided wire rod, or cable.

In FIG. 2B, the catheter sheath 22 is shown being retracted proximally,while the device anchor 24 and anchor rail 26 are expelled distallytherefrom. The exemplary device anchor 24 includes a plurality ofcircumferentially distributed and distally-directed sharp tines or barbs28 that pierce the tissue of the ventricular apex. The barbs 28 are heldin a stressed configuration within the sheath 22, and are provided withan outward elastic bias so that they curl outward upon release from thesheath. Desirably the barbs 28 are made of a super-elastic metal such asNitinol. The outward curling of the barbs 28 can be seen in both FIGS.2B and 2C, the latter showing the final relaxed configuration of thebarbs. The operation to embed the device anchor 24 may be controlledunder visualization, such as by providing radiopaque markers in andaround the device anchor 24 and distal end of the catheter sheath 22.Certain other devices described herein may be used to help position thedevice anchor 24 at the ventricular apex, as will be described. Althoughthe particular device anchor 24 shown in FIGS. 2A-2C is consideredhighly effective, other anchors are contemplated, such as shown anddescribed below, and the application should not be considered limited toone type or another.

To facilitate central positioning of the anchor rail 26 duringdeployment the device is implanted with the assistance of a fluoroscope.For example, after properly positioning the patient so as to maximizethe view of the target annulus, for example the tricuspid annulus, apigtail catheter is placed in the right ventricle and contrast injected.This allows the user to see a clear outline of the annulus and the rightventricle. At this point, a frame of interest is selected (e.g., endsystole) in which the annulus is clearly visible and the annulus toventricular apex distance is minimized. On the monitor, the outline ofthe right ventricle, the annulus, and the pulmonary artery are traced.The center of the annulus is then identified and a reference line placed90° thereto is drawn extending to the right ventricular wall. Thisprovides a clear linear target for anchoring. In a preferred embodiment,the anchor 24 is preferably located in the base of the ventricle betweenthe septum and the free wall.

Aligning the anchor rail 26 in this manner helps center the eventualpositioning of a coapting element of the system within the tricuspidleaflets. If the coapting element is offset to the anterior or posteriorside, it may get stuck in the tricuspid valve commissures resulting inleakage in the center of the valve. An alternative method is to place adevice such as a Swan Ganz catheter through the right ventricle and intothe pulmonary artery to verify that the viewing plane is parallel to theanterior/posterior viewing plane. Addition of a septal/lateral view onthe fluoroscope may be important to center the anchor in patients thathave a dilated annulus and right ventricle.

FIGS. 3A and 3B illustrate deployment of a regurgitation reductiondevice 30 including a delivery catheter 32 advanced along the anchorrail 26 to position a coapting element 34 within the tricuspid valve TV.The coapting element 34 fastens to a distal end of the delivery catheter32, both of which slide along the anchor rail 26, which has beenpreviously positioned as described above. Ultimately, as seen in FIG.3B, the coapting element 34 resides within the tricuspid valve TV, theleaflets of which are shown closed in systole and in contact with thecoapting element. Likewise, the delivery catheter 32 remains in the bodyas seen in FIGS. 3B and 5, and the prefix “delivery” should not beconsidered to limit its function. A variety of coapting elements aredescribed herein, the common feature of which is the goal of providing aplug of sorts within the heart valve leaflets to mitigate or otherwiseeliminate regurgitation. In the illustrated embodiment, the coaptingelement 34 includes an inner strut structure partly surrounded bybioprosthetic tissue, as will be described in more detail below.

In one embodiment, a short tubular collar 33 a fastens to the distal endof the delivery catheter 32 and provides structure to surround theproximal ends of a plurality of struts 35 that form a strut frame. Asecond tubular collar 33 b holds together the distal ends of the struts35 and attaches to a small ferrule (not shown) having a through borethat slides over the anchor rail 26. Each of the struts 35 has proximaland distal ends that are formed as a part of (or constrained within)these collars 33 a, 33 b and a mid-portion that arcs radially outward toextend substantially parallel to the axis of the coapting element 34.The frame shape is thus a generally elongated oval. In the illustratedembodiment, there are six struts 35 in the frame, although more or lesscould be provided. The struts 35 are desirably formed of a super-elasticmaterial such as Nitinol so as to have a minimum amount of rigidity toform the generally cylindrical outline of the frame but maximumflexibility so that the frame deforms from the inward forces imparted bythe heart valve leaflets.

The coapting element 34 may include a cover formed by one or more panelsof bioprosthetic tissue or flexible polymer sewn around the struts 35 ofthe frame. One particularly effective polymer is a polycarbonateurethane (Carbothane from Lubrizol, Bionate from DSM, ChronoFlex fromAdvansource) which has extremely good durability over long periods oftime, as opposed to materials such as Nylon used for typical catheterballoons. Alternatively, a polycarbonate silicone may also be used. Asingle axial seam may be used, though the cover is typically formed oftwo or three panels sewn together with a matching number of seams. Thetissue cover may be formed of a variety of xenograft sheet tissue,though bovine pericardial tissue is particularly preferred for its longhistory of use in cardiac implants, physical properties and relativeavailability. Other options are porcine or equine pericardium, forexample.

In the embodiment of FIGS. 3A-3B, the tissue cover has a proximal endthat is closed to fluid flow, and a distal end that is open; thus, thecover resembles a bell shape. Desirably, the axial length of the coverextends from the proximal collar 33 a approximately three-quarters ofthe way down to the distal collar 33 b, to the end of the flat sectionof the device. As mentioned above, the open bell shape desirablyfacilitates functioning of the coapting element. Namely, duringdiastole, blood flows around the coaptation element 34, while duringsystole, as the native leaflets close and contact the coaptationelement, the pressure and blood flow work to fill the interior of thecoaptation element by pushing blood in, the interior of the coaptationelement is at the same pressure as the RV and a seal is created. Thesephases of the cardiac cycle are common to both the tricuspid and mitralvalves. Generally the coaptation elements that are closed on the atrialside and open to the ventricular side move essentially like aparachute—filling in systole, and blood flowing around without collapsein diastole.

FIG. 3C is a sectional view of the right atrium and ventricle in systoleshowing a balloon-type coapting element 34, while FIG. 3D shows thetricuspid valve leaflets 38 closed around the balloon. FIGS. 3E and 3Fshow the tricuspid valve open in diastole permitting blood flow aroundthe coapting element 34. The balloon 34 provides a more passive ratherthan user-defined approach to coaptation element shape changing. In oneembodiment, the coaptation element 34 has a plurality (e.g. >20) of verythin and highly flexible struts 36 that connect between top and bottomcollars, for instance. The struts 36 thus relocate independently of oneanother, which allows leaflet motion to deform the highly compliantcoaptation element 34 into whatever shape best conforms to the remainingorifice. Since segments of the balloon 34 adjacent areas with highleaflet mobility would be compressed, the coaptation element could bedramatically oversized with respect to the regurgitant orifice size inorder to maintain coaptation in commissural regions (see FIG. 3D). Sincestruts on a mechanical balloon stray farther apart when expanded,multiple tubes could be placed within each other at alternating rotationangles in order to increase circularity and strut density.

A locking mechanism is provided on the regurgitation reduction device 30to lock the position of the coapting element 34 within the tricuspidvalve TV and relative to the fixed anchor rail 26. For example, alocking collet 40 along the length of the delivery catheter 32 permitsthe physician to selectively lock the position of the delivery catheter,and thus the connected coapting element 34, on the anchor rail 26. Thereare of course a number of ways to lock a catheter over a concentricguide rail, and the application should not be considered limited to theillustrated embodiment. For instance, rather than a locking collet 40, acrimpable section such as a stainless steel tube may be included on thedelivery catheter 32 at a location near the skin entry point and spacedapart from the location of the coapting element 34. The physician needonly position the coapting element 34 within the leaflets, crimp thecatheter 32 onto the anchor rail 26, and then sever both the catheterand rail above the crimp point.

Details of the exemplary locking collet 40 are seen in FIGS. 4A-4C. Thecollet 40 includes two short tubular grips 42 a, 42 b that areinternally threaded and engage a common externally threaded tubularshaft member 44. The delivery catheter 32 is interrupted by the collet40, and free ends of the catheter fasten within bores provided inopposite ends of the grips 42 a, 42 b. As seen in FIG. 4B, the anchorrail 26 extends through the middle of the locking collet 40, thuscontinuing the length of the delivery catheter 32. Furthermore, when thegrips 42 a, 42 b are separated from each other as seen in FIGS. 4A and4B, the anchor rail 26 slides freely through the locking collet 40.

An inner, generally tubular wedge member 46 is concentrically positionedbetween the shaft member 44 and the anchor rail 26. One or both ends ofthe wedge member 46 has a tapered surface 48 (see FIG. 4C) thatinteracts with a similarly tapered inner bore of the surrounding tubulargrip 42 a, 42 b. The wedge member 46 features a series of axial slotsextending from opposite ends which permit its diameter to be reducedfrom radially inward forces applied by the surrounding grips 42 a, 42 band shaft member 44. More particularly, FIG. 4C shows movement of thetwo grips 42 a, 42 b toward each other from screwing them together overthe threaded shaft member 44. Desirably, outward ribs or other suchfrictional enhancers are provided on the exterior of both of the grips42 a, 42 b to facilitate the application of torque in the often wetsurgical environment. Axial movement of the tapered inner bore of one orboth of the grips 42 a, 42 b forces inward the tapered surface 48 of thewedge member 46, and also the outer ends of the shaft member 44. Inother words, screwing the grips 42 a, 42 b together cams the shaftmember and a wedge member 46 inward. The dimensions are such that whenthe two grips 42 a, 42 b come together, the inward force applied by thewedge member 46 on the anchor rail 26 is sufficient to lock the deliverycatheter 32 and anchor rail.

Now with reference to FIG. 5, the entire regurgitation reduction device30 can be seen extending from the apex of the right ventricle RV upwardthrough the superior vena cava SVC and into the subclavian vein SV. Aproximal length of the delivery catheter 32 including the locking collet40 exits the subclavian vein SV through a puncture and remains implantedsubcutaneously; preferably coiling upon itself as shown. In theprocedure, the physician first ensures proper positioning of thecoapting element 34 within the tricuspid valve TV, then locks thedelivery catheter 32 with respect to the anchor rail 26 by actuating thelocking collet 40, and then severs that portion of the delivery catheter32 that extends proximally from the locking collet. The collet 40 and/orcoiled portion of the delivery catheter 32 may be sutured or otherwiseanchored in place to subcutaneous tissues outside the subclavian veinSV. It is also worth noting that since the delivery catheter 32 slideswith respect to the anchor rail 26, it may be completely removed towithdraw the coapting element 34 and abort the procedure—either duringor after implantation. The implant configuration is similar to thatpracticed when securing a pacemaker with an electrode in the rightatrium muscle tissue and the leads extending to the associated pulsegenerator placed outside the subclavian vein. Indeed, the procedure maybe performed in conjunction with the implant of a pacing lead.

FIG. 5A is a schematic diagram of a pair of native tissue leaflets 38indicating certain key dimensions used in constructing the coaptingelement. The inquiry seeks to determine a preferred height of thecoapting element, or at least the height of the leaflet contactingsurface of the elements. It is known that the length of heart valveleaflets are often mismatched, and the dimension LM indicates theleaflet mismatch as a distance along the axis of the valve. An axialdimension of a coapting element that fits within these two mismatchedleaflets will therefore have a minimum height that starts at the tip ofthe longer leaflet and extends upward approximately twice the leafletmismatch LM dimension, indicated as H_(min). To avoid inserting toolarge a structure between the leaflets, a dimension H_(max) extends fromapproximately the plane of the annulus of the leaflets (i.e., where theyattach to the surrounding wall) down to a distance into the ventriclewhich is centered at the center of the dimension H_(min). The leafletexcursion LE reflects the length along which the leaflets are known tocontact the coapting devices. That is, the leaflets first hit the deviceand then move down with the contraction of the heart. There musttherefore be enough surface length or leaflet excursion LE for theleaflets to maintain contact. In general, the axial dimension of thecoapting element should ensure enough coaptation length to accommodateleaflet mismatch and leaflet excursion without protruding too much intothe ventricle or atrium.

Coapting Elements:

As mentioned, a number of different coapting elements are described inthe present application. Indeed, the present application provides aplurality of solutions for preventing regurgitation in atrioventricularvalves, none of which should be viewed as necessarily more effectivethan another. For example, the choice of coapting element depends partlyon physician preference, partly on anatomical particularities, partly onthe results of clinical examination of the condition of the patient, andother factors.

One broad category of coapting element that is disclosed herein and hasbeen subject to testing is a flexible mechanical frame structure atleast partially covered with bioprosthetic tissue. The inner framestructure is flexible enough to react to the inward forces imparted bythe closing heart valve leaflets, and therefore undergo a shape changeto more completely coapt with the leaflets, thus reducing regurgitantjets. The bioprosthetic tissue covering helps reduce materialinteractions between the native leaflets and the inner mechanical frame.As mentioned above, the regurgitation reduction device can beeffectively deployed at either the tricuspid or mitral valves, theformer which typically has three leaflet cusps defined around theorifice while the latter has just two. The tissue-covered mechanicalballoon thus represents an effective co-optation element for both valvesby providing a highly flexible structure which is substantially inert totissue interactions.

An exemplary embodiment of this so-called “Flexible Bell CoaptationElement” consists of a pericardial tissue (or a biocompatible flexiblematerial) that is cut and sewn to create a sac/bell shape that is ableto hold liquid (blood). One embodiment is designed to sit in the valveplane such that the open end is towards the atrium and the closedportion towards the ventricle. Therefore during diastole, blood flowsinto the coaptation element and fills the sac, conversely during systoleas the native leaflets begin to close and contact the coaptationelement, the pressure and blood flow work to decrease the size of thecoaptation element by pushing blood out of the top edge sufficientlywhile still creating a seal.

Variations on the system include various design shapes at theventricular end that is closed such as a half circle, triangle, ellipseor the like. Additionally sutures on the closed end as well as axiallyalong the coaptation element better define how the element closes frominteraction with the native leaflets. Lastly a more rigid support suchas cloth, wire or other material could be sutured along the open atrialseated edge to ensure that the design remained open during the cardiaccycle. These principles apply equally to coapting elements that are opento the ventricle and closed to the atrium.

For the sake of uniformity, in these figures and others in theapplication the coapting elements are depicted such that the atrial endis up, while the ventricular end is down. These directions may also bereferred to as “proximal” as a synonym for up or the atrial end, and“distal” as a synonym for down or the ventricular end, which are termsrelative to the physician's perspective.

FIG. 6A illustrate a coapting element 90 having multiple elongatedmembers, while FIGS. 6B-6C show the tricuspid valve in both diastole andsystole, respectively, illustrating the desired coaptation with theleaflets. This coapting element 90 can be viewed in the abstract as anetwork of elongated “pixels” 92, which can be provided in variousforms, such as balloons, rods, tubes, wires, etc. It is advantageous toachieve optimal size, shape, and location of the coaptation element inorder to ensure maximal levels of regurgitation reduction in a varietyof tricuspid leaflet anatomies. Rather than consisting of one staticstructure, the coaptation element 90 comprises a network of long, thinballoons 92 of circular cross-section which would each be individuallyinflatable and deflatable at the time of implant. Thus, the coaptationelement could be analogous to a screen of “pixels” with the ability toturn on or off (inflate or deflate) any given pixel to achieve the idealcoaptation element shape, size, and location relative to the valveleaflets. The inflation medium could be designed such that it is fluidat time of implant (in order to inflate/deflate various areas of thedevice and use echo feedback to determine the optimal combination toreduce TR) but then would cure into a solid or semi-solid within theballoon for long-term stability.

The entire network of balloons 92 in the coaptation element 90 could becovered with a sleeve of pericardium or biocompatible material, withadjustable tension per the “Adjustable Size/Shape Coaptation Element”idea previously discussed. Rather than inflating/deflating individualelements in the balloon network, the cylindrical elements could be addedor deleted in any area of the network. For example, a circular “grid” ofwires could be constructed, and small cylindrical elements could beadvanced through the catheter, into the pericardial coaptation element,and into the specified region where coaptation is lacking. Thecylindrical elements could be comprised of a compressible foam or somefoam of elastic polymer, such that they would expand when slid distallyinto the coaptation element and compress when slid proximally into thedelivery catheter. This method could be superior to the previouslydescribed inflation/deflation method, since maintaining long-term steadypressure in an inflated system could prove to be challenging.

FIGS. 7A/7B show a compressible coapting element 100 with the tricuspidvalve in diastole, while FIGS. 8A/8B show the same coapting element andthe tricuspid valve in systole. This “hybrid coaptation element” 100 isfilled with a deformable fluid so as to have the ability to passivelydeform its cross-section to a shape that promotes optimal coaptationwith the native leaflets. The hybrid solid/fluid coaptation element 100desirably includes a circular mechanical frame 102 within a largerfluid-filled “sac” 104 (see FIGS. 7A and 7B). The mechanical frame 102would serve the purpose of occupying the main central regurgitantorifice, while the encompassing fluid-filled sac 104 is deformed by themotion of the leaflets, therefore allowing it to occupy any potentialoff-center regurgitant orifices in any or all of the three commissuralregions between the tricuspid leaflets. The mechanical frame 102 may becomprised of Nitinol struts, while the deformable sac 104 could be madeof pericardium or an impermeable bio-inert polymer, and the fluid couldbe a saline solution. The underlying rigid mechanical frame 102 could beany size or shape other than circular. Also, instead of fluid for thedeformable portion of the coaptation element 100, it could be possibleto use a highly compressible foam or other elastic polymer.Additionally, this device may be implemented with no internal structure,i.e. struts, but alter its shape with fluid displacement.

FIGS. 9A-9B illustrate a regurgitation reduction device 110 positionedin the right atrium/right ventricle having a three-sided frame 112 as acoaptation element, and FIGS. 10A and 10B show greater detail of thecoaptation element. FIG. 9A shows the heart in diastole during whichtime venous blood flows into the right ventricle between the opentricuspid valve leaflets and the three-sided frame 112. In the systolicphase, as seen in FIG. 9B, the tricuspid leaflets close around thecompressible frame 112, thus coapting against the frame and eliminatingopenings to prevent regurgitation.

FIG. 10B shows the desirably three-sided radial profile of the frame112, with three relatively flat convex sides 114 separated by roundedcorners 116. This rounded triangular shape is believed to faithfullyconform to the three tricuspid leaflets as they close, this betterpreventing regurgitation. Moreover, the frame 112 is desirably underfilled so that it can be compressed and deformed by the leaflets. FIG.10A also shows a preferred longitudinal profile of the frame 112, withan asymmetric shape having a gradually overall longitudinal curvature117 and an enlarged belly region 118 just distal from a midline. Theshape resembles a jalapeno pepper. Due to the curvature of the path fromthe superior vena cava SVC down through the tricuspid valve TV and intothe right ventricle RV, the overall curvature 117 of the frame 112 helpsposition a mid-section more perpendicular to the tricuspid valveleaflets, while the uneven longitudinal thickness with the belly region118 is believed to more effectively coapt with the leaflets.

FIG. 11A shows a rectangular sheet 120 of bioprosthetic tissue, and FIG.11B illustrates a coaptation element 122 formed from rolling the sheetof tissue into a cylinder. This creates a coaptation element 122 with asolid structure and no lumen to fill. Alternatively, if a morecompressible structure would be desired for ease of delivery, arelatively softer foam-based material could be used as the structure forthe coaptation element, and then a pericardial or other biocompatiblematerial could be used to coat the surface. Multiple differentthicknesses of pericardium or a biocompatible polymer (or a combinationof the two) could be used to achieve various stiffness levels in thecoaptation element. The foam could be used with a biocompatiblecovering, or the foam could be delivered uncovered, with the intent topromote pannus formation on the device surface, therefore relying on thenatural mechanisms of the heart to provide the device with abiocompatible coating.

Adjustable Size/Shape Coaptation Elements:

If the size and/or shape of the coaptation element were to be adjustedin vivo, the surface area of the resulting device would be significantlydifferent than the default situation. Thus, the idea of an adjustablecoaptation element supported by a multi-strut mechanical frame, forexample, would necessitate independent control of the pericardium orbiocompatible covering in order to maintain a taught and smoothcoaptation surface. For example, if an equilateral triangular coaptationelement were to be adjusted to a much narrower scalene triangle, anindependent catheter shaft connected to the proximal end of thebiocompatible covering could be pulled, proximally in order to accountfor the decrease in coaptation element surface area and thus maintain aproperly rigid coaptation surface. This concept could be applied withany number of struts greater than two in order to achieve a variety ofcoaptation element shapes (i.e. ellipse, crescent, acute triangles).Anything between one or all of the mechanical struts could be containedin a rotation channel to alter their orientation around thecircumference of the catheter.

FIGS. 12A-12C are longitudinal sectional views of an “active” coaptationelement 130 of the present application forming several different shapes.Given that tricuspid valve anatomy is highly variable between patientsin terms of leaflet shapes, sizes, and coaptation surface locations, itcould be favorable to develop a coaptation element capable of adjustingshape and size during the implant procedure in order to optimizereduction of tricuspid regurgitation (TR) in a patient-specific manner.An adjustable design feature could be achieved with a “mechanical frame”in which a number of metallic (preferably Nitinol) struts 132 aresurrounded by a tube of pericardium 134 or some other bio-inertmaterial, around which the native tricuspid leaflets could coapt andform a seal. The struts 132 would be attached at their distal ends to aninner catheter 136, and at their proximal ends to an adjustable positionintermediate catheter 138 which, when pushed distally, causes themechanical frame struts 132 to bend outward, thus increasing thecoaptation element size. An outer catheter 140 to which a proximal endof the tube of pericardium 134 attaches also moves distally from beingpulled by outward expansion of the pericardium, as in FIG. 12C. The Asfor adjustable shape, take the case of a triangular element with threeindependent struts, for example—if one of these struts were locatedwithin a circumferential “channel” within the catheter body around whichthe strut could be rotated and locked into a new circumferentialposition, the user could change the shape of the coaptation element froman equilateral triangle to any degree of scalene triangle. This featurecould potentially be useful for adjusting the surfaces of the coaptationelement to align with the native leaflet anatomy and thus allow foroptimal coaptation.

For example, FIGS. 13A and 13B schematically illustrate an aggregationof three rectangular frames 142 that are axially retained with respectto one another and rotational about a catheter or inner hub structure144. As indicated by the movement arrows, the frames can not only rotateabout but can slide linearly along radial lines relative to the innerhub structure 144. Although not shown in the figures, a tissue coveringis provided around the frames to act as a barrier preventinginflammation and other deleterious side effects from contact with thematerial of the frames 142 and the tissue leaflets. The threerectangular structures 142 would have the ability to rotate as well astranslate in response to forces from leaflets coapting against thedevice, thus passively changing shape to shift cross-sectional area ofthe coaptation element away from portions of the valve with high leafletmobility and instead to areas with low leaflet mobility and highlikelihood of regurgitant jets. The struts 142 may be thin as wire toallow for maximal flexibility and may be oriented in various directions.

FIG. 13B illustrates one possible outcome of interposition of theco-opting element having the frames 142 during diastole when thetricuspid valve leaflets close around the device as well as push theopposite side of the rectangle into a commissure. The independentlyrotating rectangular frames 142 thus dynamically react to forces exertedthereon by the tricuspid valve leaflets and thus better coapt againstthe leaflets.

FIGS. 14A/14B and 15 illustrate a coapting element 150 having a cagestructure 152 and ball valve 154 therein. The cage 152 may be comprisedof structure similar to the previously described mechanical frame, and abio-inert polymeric ball 154 is housed within the cage. This ball couldbe compressible (or later expandable) in order to fit through theinitial delivery catheter. In order to provide a surface for theleaflets to wrap and form a seal around, an impermeable polymer or otherbiocompatible surface 156 could be used to cover an upper portion of thecylindrical cage 152 (towards the atrium). During diastole, fluidinertial forces would push the ball 154 down to the ventricular side ofthe cage, thus allowing flow to pass through the device into theventricle without any obstruction. During systole, ventricular pressureand fluid inertial forces would push the ball up to the atrial side ofthe cage into the portion of the cage with the impermeable covering,thus forming a seal to prevent regurgitant flow through the device (thenative leaflets wrap against the element to prevent regurgitant flowaround the device).

Rather than a ball to seal the inner side of the coaptation element cage150, a cylindrical plug could be used instead. In this case, it wouldnot necessarily be critical to cover the upper portion of the implantwith the impermeable surface 156, since the plug could also function asthe surface on which the native leaflets coapt. The cage could beexpandable or self-expanding (Nitinol) in order to facilitate passagethrough a small profile delivery catheter. The polymer ball could beeither compressible, inflatable, or expandable at time of implant inorder to fit through the same delivery catheter.

FIG. 16 is a view of another coapting element 160 having a “sail” 162extending laterally from one side of an otherwise smooth or cylindricalbody 164 that catches regurgitant flow and adjusts the position of thecoapting element. The sail 162 could be positioned just on one side, asshown, or around one-quarter or one-half of the device, or any otherportion more or less.

Experiments in a bench-top pulsatile flow model with porcine hearts hasshown that if the coaptation element 160 is anchored to a non-ideallocation in the right ventricle (i.e. at the RV apex close to theanterior or posterior wall), the motion of the native leaflets cannotalways self-center the coaptation element towards the expected centrallocation of the regurgitant orifice. If the coaptation element getsstuck in a non-central location, higher levels of TR can be expected.Aside from ensuring central anchor location, one potential way toaddress this issue could be to equip the coaptation element with aseries of individually adjustable “flaps” or “sails” around itscircumference which in the default state would lie flat along thecoaptation element, but could each be deployed on a hinge to catchsystolic fluid flow in the RV and therefore pull the coaptation elementin a particular direction, such as to a central position. The series offlaps could each be tested to determine which is in the correct locationto induce systolic movement of the coaptation element towards theannulus center. Any number of sails or flaps could be used, preferablygreater than two. The hinge point could be at the proximal end of thesail, such that it deploys upwards, or at the distal end of the sail,such that it deploys downwards.

FIGS. 17A and 17B are views of a self-centering coapting element 170that adjusts to regurgitation by laterally adjusting position. FIGS.18A-18B illustrate the coapting element 170 with a generally smooth orcylindrical body 172 and a circumferential skirt 174 shown contractedand expanded, respectively. As with the sails discussed above, the skirt174 normally remains bias against the cylindrical body 172 (or othershape), and all or a portion thereof pivots outward when caught byregurgitant flow to move the coapting element 170 toward that flow, suchas to a central position. In this way, the coapting element 170dynamically reacts to fluctuating fluid flows around the device to movein desired directions to close the regurgitant flow.

FIGS. 19A and 19B show a still further regurgitation reduction device180 including a flapper valve 182 that interacts with the tricuspidvalve leaflets. The flapper valve 182 is anchored by a tether 184 to astent 186 pre-positioned within a coronary sinus opening to the rightatrium. Rather than occupying the regurgitant orifice with a longcylindrical device, the coaptation surface is formed generally acrossthe tricuspid valve by the circular disk or coaptation “lid” 182(essentially a cylinder but with negligible length). The disk 182 couldbe a metallic structure covered with pericardium or a bio-inert polymersuch as silicone, and it is desirably anchored in place via theconnecting member 184 and cylindrical stent 186. In order to minimizerestriction of flow during diastole, the disk could be mounted on ahinge mechanism 188 such that it would hinge downwards (to alignvertically) during diastole and hinge upwards (to align horizontally)during systole. A hinge feature could allow for significant oversizingof the disk with respect to the regurgitant orifice area, thus ensuringproper coaptation from the leaflets even if further RV remodeling andannular dilatation were to occur. Rather than anchoring the lid elementin the coronary sinus, it could be anchored via a shaft to the RV apex,or alternatively from the superior vena cava.

FIGS. 20A and 20B show a tricuspid valve interacting with aregurgitation reduction device 190 having a coil-spring coapting element192 anchored via a tether 194 to a stent 196 within a coronary sinus.When subject to diastolic flow, as in FIG. 20B, the coil-spring coaptingelement 192 would expand downwards towards the RV apex and thereforeallow flow through the spring. During systole, as in FIG. 20A, thecoil-spring coapting element 192 compress from a conical spring into aflat disk, similar to the previously described embodiment.

One potential challenge of a static coaptation element within thetricuspid valve annulus could be diastolic stenosis, i.e. restriction ofblood flow from the right atrium to the right ventricle during diastole.In patients with an excessively large regurgitant orifice, sizing thedevice for proper coaptation during systole could have consequences indiastole. To address this issue, a coaptation element 200 could beattached to a flexible metallic spring 204 connected to anchor 202,therefore allowing the coaptation element to move in and out of theannulus plane during systole and diastole, respectively (see FIGS. 21Aand 21B). During systole, as in FIG. 21B, the pressure gradient as wellas fluid inertial forces would cause the spring 204 to extend, andduring diastole the spring constant as well as fluid inertial forceswould cause the spring to contract. Instead of just one spring distal tothe coaptation element, a spring could be placed on both sides in orderto increase mobility. Alternatively, with one spring, the “home”position of the coaptation element (i.e. with no force from the springor fluid) could either be at the annulus plane or below the annulusplane in the RV. In the former case, inertial forces of diastolic flowwould be required to move the coaptation element down out of the annulusplane during diastole, and in the latter case, both inertial forces ofsystolic flow and forces from the RV/RA pressure gradient could move thecoaptation element up to the annulus during systole.

Anchors and Alternative Anchor Placement:

The following list of embodiments presents additional design ideas forthe catheter railing and anchoring system:

FIGS. 22 and 23 are views of alternative anchoring members utilizingconical coil springs. One potential challenge of some proposed helicalanchors is the limited surface area on which the anchor can “grab”tissue given its short cylindrical length (2 mm). In order to maximizethe area of tissue contact over the 2 mm length of the anchor, amodified helical anchor 210 could be developed which has a conicalshape, i.e. a circular cross-section of increasing size towards thedistal end. The conical spring anchor 210 could be provide at the end ofan anchor rail 212, as previously described. Such an anchor design couldincrease retention force by increasing the cross-sectional area ofcontact between the anchor coil and the tissue. Additionally, as theinitial cut of the anchor 210 into the tissue would be largest followedby decreasing coil diameter as the anchor is screwed in, the anchorcould effectively “cinch” in a volume of tissue into a compacted space.Such a feature could potentially minimize the risk for anchor tear-outby increasing the local tissue density at the anchor site. The conicalspring 210 could be comprised of any shape memory material capable ofcollapsing or wrapping down to a smaller constant diameter to fitthrough a catheter lumen, then capable of expanding to the naturalconical shape upon exiting the delivery sheath into the RV.

Alternatively, a conical anchor 214 could be connected via an elongatedhelical section 216 at its proximal end designed to remain in the RV(not screwed into the tissue but directly next to it), such as shown inFIG. 23. The elongated helical section 216 provides shock absorptioncapabilities against compressive/tensile stresses, thus reducingtear-away stresses on the RV apex, and also flexibility capabilitiesunder bending stresses.

Using helical structures for anchoring the devices described herein inthe right ventricle holds a number of advantages (e.g. ease of delivery,acute removability, minimal tissue damage, etc.). However, one potentialchallenge could be the tendency of a helical structure to “unscrew”itself out of the tissue, either acutely or over time due to thecontractile motions of the ventricle. To address this issue, an anchorsystem in FIG. 24 includes concentric corkscrew anchors; an inner anchor220 at the end of an inner tube 222, and an outer anchor 224 on the endof an outer tube 226. FIGS. 24A-24C illustrate steps in installation ofthe anchoring device, in which first the inner anchor 220 having aclockwise orientation is screwed into the tissue. Next, the slightlylarger second anchor 224, having a counterclockwise orientation, and itstube 226 slide over the first anchor 220 and tube 222 and screws intothe tissue in the opposite direction. Finally, the two anchors could befixed together with a locking mechanism (e.g., pin-through-hole style).The resulting structure would resist unscrewing out of the tissue, sinceeach helical coil opposes the twisting motion of the other.

FIG. 25 shows another configuration with a helical corkscrew-type anchor230 on the end of a tube 232, and a pair of struts 234 that may beindependently expelled from the distal end of the tube into contact withthe tissue surrounding the anchor. Rather than screwing in a secondrelatively similar anchor in the opposite direction to preventtwist-out, the struts 234 pass through the tube lumen and extendoutwards in an L-shaped manner to provide an anti-rotation anchor to thedevice. These struts 234 should be thick enough to press against the RVapex tissue and apply friction thereto to prevent twisting motion of theanchor 230.

In an alternative approach to enabling fine control over the position ofthe coaptation element within the valve plane, as seen in FIG. 26, aseries of two or more anchors 240 could be deployed in various areas ofthe RV (including possibly the papillary muscles). The attached anchorrails 242 could all extend through a lumen of the coaptation element(not shown). In order to re-position the coaptation element, the tensionon any given anchor rail 242 could be altered independently at theaccess site, thus increasing or decreasing the degree of tethering onthe coaptation element in a certain direction. For example, to move thecoaptation element to a more posterior position within the valve, theanchor rail 242 corresponding to the more posterior anchor 240 could bepulled more taught. Once the desired position is achieved, the relativelengths of all the anchor rails could be fixed with respect to thecoaptation element catheter via a locking or clamping mechanism at theproximal end of the device. The anchor rails referenced previously couldinstead be cable wires (with no lumen) in order to minimize the profileof the coaptation element catheter given that multiple anchorattachments will need to fit within the device inner lumen. In order tofacilitate easily distinguishing which cable attaches to which anchor,the catheter could contain a series of lumens (at least two) for cablewires which would be labeled based on anatomical location of thecorresponding anchor. Therefore, at the proximal end of the device, itwould be clear which cable would be required to pull in order totranslate the coaptation element in a certain direction.

FIGS. 27A and 27B show operation of a centering balloon 250 that helpsensure proper positioning of an anchor 252 at the apex of the rightventricle. A series of experiments in a bench-top pulsatile flow modelwith porcine hearts has emphasized the importance of RV anchor positionfor achieving central location of the coaptation element within thevalve. Thus, it may be necessary to utilize an accessory catheter 254for the present device to help facilitate delivery of the anchor 252 tothe ideal location within the ventricle, or the centering balloon 250may be mounted on the distal end of the delivery/anchoring catheteritself. One such approach relies on using the annulus itself to guidethe anchor shaft. For instance, a perfusion balloon 250 large enough tofill the entire valve could be inflated within the tricuspid annulus,therefore counting on opposition between the annulus and the perfusionballoon to orient the angle of the catheter lumen directly normal to andthrough the center of the valve plane. FIG. 27A shows the unwantedposition of the anchor 250 before balloon inflation, while FIG. 27Bshows the desired positioning at the RV apex after the balloon 250 isinflated. At this point, the anchor shaft would pass through the lumenof the perfusion balloon catheter (either an accessory catheter or thedelivery catheter itself), which is oriented so as to guide the anchorto the ideal central location along the anterior-posterior axis of theRV apex. The centering balloon 250 allows the delivery system to trackinto the RV while avoiding chords and ensuring central placement ratherthan between leaflets.

FIG. 28 illustrates a step in directing an anchoring catheter 260 to theapex of the right ventricle using an L-shaped stabilizing catheter 262secured within a coronary sinus. This configuration addresses thechallenge of guiding the anchor delivery. The catheter 262 is capable ofdeflecting into an L-shape, and would be advanced from the SVC, into theright atrium, then into the coronary sinus, which would provide astabilizing feature for the guide catheter that is within a direct lineto the tricuspid annulus. The catheter 262 could be maneuvered furtherin or out of the coronary sinus such that the “elbow” of the L-shape ispositioned directly above the center of the valve, then the anchorcatheter 260 could be delivered through the lumen of the guide catheter262 and out a port at the elbow of the L-shape. A temporary stiffening“stylet” (not shown) could be used through the anchor rail lumen toensure the anchor is delivered directly downwards to the ideal point atthe RV apex.

If any of the previously described anchoring options involving anycombination of the RV, SVC, and IVC prove to be undesirable, thecoaptation element could instead be anchored directly to the annulus. Asshown in FIG. 29, a series of at least two anchors 270 (similar to thehelical RV anchors) could be deployed into the fibrous portion of theannulus, then cables or stabilizing rods 272 could be used to hang orsuspend the coaptation element 274 within the annulus plane. Eachsupport cable or rod 272 would need to be relatively taught, so as toprevent motion of the device towards the atrium during systole. Anynumber of supports struts greater than two could be utilized. Thesupport cables for suspending the coaptation element from the annuluscould be relatively flexible, and thus the position and mobility of thedevice would be altered via tension in the cables. Alternatively, thesupport elements could be relatively stiff to decrease device motion,but this would require changing anchor position to reposition thecoaptation element. Although an anchor 276 to the RV apex is shown, thedual annulus anchors 270 might obviate the need for a ventricularanchor.

The general concept of cylindrical stent-based anchor mechanisms for thedevice could be applied in other structures near the tricuspid valvesuch as the coronary sinus. For instance, FIG. 30 illustrates anadjustable stabilizing rod 280 mounted on a delivery catheter 282 andsecured to an anchor 284 within the coronary sinus. The stabilizing rod280 attaches via an adjustable sleeve 286 to the catheter 282, thussuspending the attached coapting element 288 down into the regurgitantorifice. A sliding mechanism on the adjustable sleeve 286 permitsadjustment of the length between the coronary sinus anchor 284 and thecoaptation device 288, thus allowing positioning of the coaptationelement at the ideal location within the valve plane. Once again, thesecuring and adjustment mechanism 284, 286 are within a direct line tothe tricuspid annulus so as to facilitate positional adjustment thereof.For further stability, this coronary sinus anchoring concept could alsobe coupled with a traditional anchor in the RV apex, as shown.

While venous access to the RV through the subclavian vein and into thesuperior vena cava is a routine procedure with minimal risk forcomplications, the fairly flat access angle of the SVC with respect tothe tricuspid valve plane presents a number of challenges for properorientation of the present coaptation element within the valve. If thecatheter were not flexible enough to achieve the correct angle of thecoaptation element with respect to the valve plane by purely passivebending, a flex point could be added to the catheter directly proximalto the coaptation element via a pull wire attached to a proximal handlethrough a double lumen extrusion. For instance, FIG. 31 illustrates analternative delivery catheter 290 having a pivot joint 292 just abovethe coapting element 294 for angle adjustment. If a given combination ofSVC access angle and/or RV anchor position resulted in a crookedcoaptation element within the valve plane, the catheter 290 could bearticulated using the pull wire (not shown) until proper alignment isachieved based on feedback from fluoroscopic views.

Additional flex points could be added to further facilitate control ofdevice angle, e.g. another flex point could be added distal to thecoaptation element 294 to compensate for the possible case that the RVwall angle (and thus the anchor angle) is skewed with respect to thevalve plane. This would require an additional independent lumen withinthe catheter body 290 to facilitate translation of another pull wire tooperate the second flex feature. Alternatively, if a single flex pointproximal to the coaptation element were determined to be sufficient fororienting the device, and if the catheter were rigid enough to resistthe forces of systolic flow, the section 296 of the device distal to thecoaptation element could be removed all together. This would leave onlyone anchoring point for the device in the SVC or subcutaneously to thesubclavian vein. Also, as an alternative to an actively-controlled flexpoint, the catheter could contain a shape-set shaft comprised of Nitinolor another shape memory material, which would be released from a rigiddelivery sheath into its “shaped” form in order to optimize device anglefrom the SVC. It could be possible to have a few catheter options ofvarying pre-set angles, yet choose only one after evaluation of theSVC-to-valve plane angle via angiographic images.

Instead of using an active mechanism within the catheter itself tochange its angle, another embodiment takes advantage of the surroundinganatomy, i.e. the SVC wall. FIGS. 32A and 32B show two ways to anchorthe delivery catheter 300 to the superior vena cava SVC for stabilizinga coapting element 302. For example, a variety of hooks or anchors 304could extend from a second lumen within the catheter 302 with theability to grab onto the SVC wall and pull the catheter in thatdirection (FIGS. 32A and 32B). Alternatively, a stiffer element couldextend outwards perpendicular to the catheter axis to butt up againstthe SVC wall and push the catheter in the opposite direction. The SVC iswithin a direct line to the tricuspid annulus, thus rendering relativelyeasy the adjustment of the coapting element 302. For especiallychallenging SVC geometries, such a mechanism could potentially be usefulfor achieving better coaxial alignment with the valve.

FIGS. 33A and 33B show an active regurgitation reduction device 310having pull wires 312 extending through the delivery catheter 314 foraltering the position of the coapting element 316 within the tricuspidvalve leaflets. If the coapting element 316 is located out of the middleof the valve leaflets such that it does not effectively plug anyregurgitant jets, which can be seen on echocardiography, then one of thepull wires 312 can be shortened or lengthened in conjunction withrotating the catheter 314 to reposition the coapting element 316, suchas seen from FIG. 33A to FIG. 33B.

Although pacemaker leads are frequently anchored in the right ventriclewith chronic success, the anchor for the present device would seesignificantly higher cyclic loads due to systolic pressure acting on thecoaptation element. Given that the right ventricle wall can be as thinas two millimeters near the apex and the tissue is often highly friablein patients with heart disease, anchoring a device in the ventricle maynot be ideal. An alternative anchoring approach could take advantage ofthe fairy collinear orientation of the superior and inferior vena cava,wherein, as seen in FIG. 34, two stent structures 320, 322 wouldeffectively “straddle” the tricuspid valve by expanding one in thesuperior vena cava and the other in the inferior vena cava. Thecoaptation element 324 would then hang down through the tricuspid valveplane from an atrial shaft 326 attached to a connecting wire or rod 328between the two caval stents 320, 322. In order to resist motion of thecoaptation element under systolic forces, the shaft 326 from which thecoaptation element 324 hangs would be fairly rigid under compressive andbending stresses. The coaptation element 324 would desirably bepositioned within the valve using a sliding mechanism along theconnecting rod 328 between the two caval stents. Once again, the directaccess to the tricuspid annulus provided by the connecting rod 328between the two caval stents greatly enhances the ability to easilyposition the coaptation element 324.

The coaxial orientation of the SVC and IVC could also be leveraged fordelivering an anchor into the RV. A delivery catheter could be passedthrough the SVC into the IVC, and a “port” or hole off the side of thedelivery catheter could be aligned with the center of the valve. At thispoint, the anchor could be passed through the lumen of the deliverysystem and out the port, resulting in a direct shot through the centerof the annulus and to the RV wall in the ideal central anchor location.

This concept could potentially be applied to the left side of the heartas well, to address mitral regurgitation. A coaptation element couldreside between the mitral valve leaflets with anchors on both theproximal and distal ends: one attaching to the septal wall, and theother anchoring in the left atrial appendage. The septal anchor could bea helical or hook-style anchor, whereas the left atrial appendage anchorcould be an expandable metallic structure with a plurality of struts orwireforms designed to oppose against the appendage wall and providestability to the coaptation element.

Pacemaker leads frequently lead to tricuspid regurgitation (TR) bypinning a leaflet or interfering with leaflet mobility. In thisparticular embodiment, a device, a gap filler, is designed to beintroduced over the offending pacemaker lead (of course, applicable alsoto those with organic tricuspid regurgitation and a pacemaker lead inplace). The invention is a tricuspid regurgitant volume gap filler thatis placed over the existing pacemaker lead via a coil wound over thelead or a slit sheath approach, which acts like a monorail catheter. Thegap filler catheter is advanced over the pacemaker lead and thetricuspid regurgitation is evaluated by echo while the monorail gapfiller device is placed into the regurgitant orifice. The proximal endof the gap filler allows for crimping and truncating the catheterpost-balloon inflation or gap filler deployment. This mates the monorailgap filler to the pacemaker lead at the proper position within thetricuspid valve.

FIGS. 35-36 are schematic views of a coapting element 330 mounted forlateral movement on a flexible delivery catheter 332 that featurescontrolled buckling. It is challenging to reposition the coaptationelement 330 from an off-center location to the ideal central locationwithin the valve plane, given a fixed angle from the SVC and a fixedanchor position in the RV. The device catheter 332 could be comprised ofa fairly stiff shaft except for two relatively flexible regions 334, 336directly proximal and distal to the coaptation element section. Thefarthest distal section of the coaptation catheter 332 could be lockeddown relative to the anchor rail over which it slides, and then thecatheter 332 could be advanced distally thus compressing it and causingthe two flexible sections 334, 336 to buckle outwards and displace thecoaptation element laterally with respect to the catheter axis (see FIG.35C). At this point, the user could employ a combination of sliding androtating of the catheter to reposition the coaptation element 330 withinthe valve using short-axis echo feedback. Instead of locking the distalend of the catheter onto an anchor rail before adjustment, if thecatheter were comprised of multiple lumens, the outer lumen could slidedistally relative to the inner lumen, thus producing the same bucklingeffect.

In another embodiment, not shown, an alternative approach could be torely on the contractile motion of the heart to move a tapered coaptationelement in and out of the tricuspid valve plane. A tapered coaptationelement, with a smaller cross-section proximally (towards the atrium)and larger cross-section distally (towards the ventricle), would beattached to a rigid distal railing and anchor. During systoliccontraction, the anchor and therefore the attached coaptation elementwould move towards the annulus, thus allowing the tricuspid leaflets tocoapt around the larger cross-section of the device. Conversely,diastolic expansion of the RV would bring the anchor and therefore thecoaptation element downwards such that the smaller cross-section of thedevice is now within the annulus plane, thus minimizing diastolicstenosis. A combination of a tapered element with a spring could be usedif RV wall motion towards the annulus is not sufficient to move thedevice.

While the foregoing is a complete description of the preferredembodiments of the invention, various alternatives, modifications, andequivalents may be used. Moreover, it will be obvious that certain othermodifications may be practiced within the scope of the appended claims.

What is claimed is:
 1. A system for delivering a coaptation member to aposition within native tricuspid heart valve leaflets to reduceregurgitation therethrough, comprising: a ventricular anchor on a distalend of a flexible rail having a length sufficient to extend from outsidethe body through the subclavian vein and past the native tricuspidannulus into the right ventricle, the ventricular anchor configured tobe anchored within the right ventricle; a coaptation member on a distalend of a delivery catheter configured to be advanced from outside thebody over the flexible rail until the coaptation member is positionedwithin the native tricuspid heart valve leaflets, wherein the coaptationmember comprises a plurality of elongated members in contact with oneanother along their lengths and held together at opposite ends, theelongated members being capable of repositioning with respect to oneanother from external forces; wherein the position of the coaptationmember is adjustable along the flexible rail; and a locking colletcarried by the catheter for locking the position of the deliverycatheter relative to the flexible rail by clamping onto the flexiblerail, the locking collet being sized to enable it to be subcutaneouslysecured immediately outside the subclavian vein.
 2. The system of claim1, wherein the locking collet includes two internally threaded tubulargrips each attached to separate sections of the delivery catheter andengaging a common externally threaded tubular shaft member through whichthe flexible rail passes, and a tubular wedge member interposed betweenthe tubular shaft member and the flexible rail, wherein clamping thelocking collet onto the flexible rail comprises screwing the tubulargrips toward each other over the tubular shaft member to cam the wedgemember inward.
 3. The system of claim 1, wherein the plurality ofelongated members are covered with a sleeve of pericardium orbiocompatible material.
 4. The system of claim 1, wherein the pluralityof elongated members comprise thin balloons that are individuallyinflatable and deflatable.
 5. The system of claim 4, further includingan inflation medium for the plurality of elongated members that is fluidat time of inflation and cures into a solid or semi-solid over time. 6.The system of claim 1, wherein the plurality of elongated memberscomprise tubes.
 7. The system of claim 1, wherein the elongated membersare configured to be added or deleted as needed to reduce regurgitationthrough the tricuspid valve.
 8. A system for delivering a coaptationmember to a position within native tricuspid heart valve leaflets toreduce regurgitation therethrough, comprising: a ventricular anchor on adistal end of a flexible rail having a length sufficient to extend fromoutside the body through the subclavian vein and past the nativetricuspid annulus into the right ventricle, the ventricular anchorconfigured to be anchored within the right ventricle; a first catheterhaving a balloon thereon configured to be advanced from outside the bodyover the flexible rail until the balloon is positioned substantiallywithin the tricuspid heart valve leaflets, the balloon on the firstcatheter being inflatable to center the flexible rail within thetricuspid annulus; a coaptation member on a second catheter advanceableover the flexible rail until the coaptation member is positioned withinthe native tricuspid heart valve leaflets, wherein the second catheterincludes a pair of relatively flexible regions directly proximal anddistal to the coaptation member and a distal section of the secondcatheter is adapted to lock down on the flexible rail, wherein aposition of the coaptation member within the tricuspid annulus may beadjusted by advancing and compressing the second catheter to cause thetwo flexible sections to buckle and displace the coaptation memberlaterally with respect to an axis of the second catheter; wherein theposition of the coaptation member is adjustable along the flexible rail;and a lock carried by the second catheter for locking the position ofthe second catheter relative to the flexible rail by clamping the lockonto the flexible rail.
 9. The system of claim 8, wherein a spring isprovided on the flexible rail between the coaptation member and theventricular anchor so that the coaptation member can move axially withrespect to the tricuspid annulus from compression and expansion of thespring.
 10. The system of claim 8, wherein the ventricular anchorcomprises a pair of concentric corkscrew anchors, one having a clockwiseorientation and the other having a counterclockwise orientation.
 11. Thesystem of claim 8, wherein the coaptation member comprises a frameformed from a plurality of struts that supports a bell-shaped tissuecover formed by one or more panels of bioprosthetic tissue or flexiblepolymer sewn around the struts of the frame, the coaptation member beingopen toward the right ventricle and closed toward the right atrium. 12.The system of claim 8, further including a pair of pull wires extendingthrough the second catheter for altering the position of the coaptingmember within the tricuspid valve leaflets, wherein the step ofadjusting the position of the coaptation member within the tricuspidannulus includes pulling one of the pull wires in conjunction withrotating the second catheter.
 13. The system of claim 12, wherein thepull wires are connected to the coaptation member for angular adjustmentof the coaptation member at the flexible region directly proximal to thecoaptation member.
 14. A system for delivering a coaptation member to aposition within native tricuspid heart valve leaflets to reduceregurgitation therethrough, comprising: a ventricular anchor on a distalend of a flexible rail having a length sufficient to extend from outsidethe body through the subclavian vein and past the native tricuspidannulus into the right ventricle, the ventricular anchor configured tobe anchored within the right ventricle; a coaptation member on a distalend of a delivery catheter configured to be advanced from outside thebody over the flexible rail until the coaptation member is positionedwithin the native tricuspid heart valve leaflets, wherein the coaptationmember comprises a plurality of elongated members of circularcross-section in contact with one another along their lengths and heldtogether at opposite ends, the elongated members being capable ofrepositioning with respect to one another from external forces; asecondary anchor for the coaptation member configured to attach to apoint above the tricuspid annulus open to the tricuspid annulus; whereinthe position of the coaptation member is adjustable along the flexiblerail; and a lock configured to lock the position of the deliverycatheter relative to the flexible rail.
 15. The system of claim 14,wherein the secondary anchor comprises a stent adapted to be securedwithin a coronary sinus opening to the right atrium, and the coaptationmember connects via a tether to the stent.
 16. The system of claim 14,wherein the secondary anchor comprises a pair of secondary anchorssecurable directly to the tricuspid annulus, and the coaptation memberis adapted to be suspended within the annulus via flexible cablesattached to the secondary anchors.
 17. The system of claim 14, whereinthe secondary anchor comprises a tissue anchor securable within acoronary sinus opening to the right atrium, and the delivery catheterconnects via an adjustable sleeve and a rod to the tissue anchor,wherein the adjustable sleeve and rod permit adjustment of the relativepositions of the tissue anchor and the coaptation member.
 18. The systemof claim 14, wherein the delivery catheter connects directly to thesuperior vena cava via an anchor.
 19. The system of claim 14, whereinthe secondary anchor comprises two stent structures, one expanded in thesuperior vena cava and the other in the inferior vena cava, and thecoaptation member connects via a connecting wire or rod to both of thetwo stent structures.
 20. The system of claim 14, wherein the pluralityof elongated members are covered with a sleeve of pericardium orbiocompatible material.